/*
 * Copyright 2013-2023 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.alibaba.cloud.nacos.parser;

import java.io.IOException;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.ObjectMapper;

import org.springframework.boot.env.OriginTrackedMapPropertySource;
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.Resource;

/**
 * Forked from com.alibaba.cloud.nacos.parser.NacosJsonPropertySourceLoader.java
 *
 * @author zkz
 */
public class NacosJsonPropertySourceLoader extends AbstractPropertySourceLoader {

  /**
   * constant.
   */
  private static final String VALUE = "value";

  /**
   * Returns the file extensions that the loader supports (excluding the '.').
   * @return the file extensions
   */
  @Override
  public String[] getFileExtensions() {
    return new String[] {"json"};
  }

  /**
   * Load the resource into one or more property sources. Implementations may either
   * return a list containing a single source, or in the case of a multi-document format
   * such as yaml a source for each document in the resource.
   * @param name the root name of the property source. If multiple documents are loaded
   * an additional suffix should be added to the name for each source loaded.
   * @param resource the resource to load
   * @return a list property sources
   * @throws IOException if the source cannot be loaded
   */
  @Override
  @SuppressWarnings("unchecked")
  protected List<PropertySource<?>> doLoad(String name, Resource resource)
      throws IOException {
    Map<String, Object> result = new LinkedHashMap<>(32);
    ObjectMapper mapper = new ObjectMapper();
    // [fix issue #3043] support comment in json config
    mapper.configure(JsonParser.Feature.ALLOW_COMMENTS, true);
    Map<String, Object> nacosDataMap = mapper.readValue(resource.getInputStream(),
        LinkedHashMap.class);
    flattenedMap(result, nacosDataMap, null);
    return Collections.singletonList(
        new OriginTrackedMapPropertySource(name, this.reloadMap(result), true));
  }

  /**
   * Reload the key ending in `value` if need.
   */
  protected Map<String, Object> reloadMap(Map<String, Object> map) {
    if (map == null || map.isEmpty()) {
      return null;
    }
    Map<String, Object> result = new LinkedHashMap<>(map);
    for (Map.Entry<String, Object> entry : map.entrySet()) {
      String key = entry.getKey();
      if (key.contains(DOT)) {
        int idx = key.lastIndexOf(DOT);
        String suffix = key.substring(idx + 1);
        if (VALUE.equalsIgnoreCase(suffix)) {
          result.put(key.substring(0, idx), entry.getValue());
        }
      }
    }
    return result;
  }
}
